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PORTLAND, Ore. (AP) - A powerful winter storm moved into the Pacific Northwest overnight and is expected to linger into Monday, delivering strong winds and rain in some places and heavy snowfall and whiteout conditions in others.

Towering waves also are expected, but the storm wasn't limited to the coast and mountains.

Liana Ramirez, a National Weather Service forecaster in Portland, said the wind's effect were more severe because it's coming directly from the south, instead of the season's usual southwesterly and westerly winds. That lead to trees toppling onto power lines.

Thousands of residents experienced power outages Sunday in Corvallis, Astoria, North Bend and elsewhere. Over 20,000 customers were in the dark Monday morning according to posts on utility websites (see links below).

The blustery weather lead to towering seas, with up to 30-foot waves on Northwest coastlines. Forecasters issued a flood watch for the north Oregon coast, with the likelihood of tidal overflows and minor coastal flooding, the Oregonian reported.

As wind and rain pummeled the coast and Willamette Valley, the Cascade Mountains in Washington and Oregon were getting hit with snow, with as much as 3 feet of powder in 36 hours.

A blizzard warning remained in effect until Monday evening. KATU Meteorologist Rhonda Shelby said the freezing level will drop during the day on Monday to about 1,000 feet, making snow in the hills around Portland a possibility.

"Many of you will see snow flying this week," Shelby said in a post to Twitter. She said to expect a rain-snow mix on the valley floor and at the coast range tonight with up to an inch of snow sticking near 1'000 feet tonight.

At higher elevations, visibility is expected to be a quarter-mile or less from the blowing snow, with whiteout conditions at upper elevations and possibly along mountain passes.

KTVZ reported more slide-off and rollover crashes occurred Sunday morning after a string of at least a dozen Saturday evening and night. Police said most likely involved drivers going too fast for the conditions.

Because of the dangerous conditions, the Weather Service recommended no travel in the Cascades unless absolutely necessary. It says motorists who do need to travel should pack winter survival kits with flashlights, food, water and blankets.

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